空间查询和属性查询是常用的两种对数据的检索与查询方式,在本节,将讲述Arcgis for Js下如何实现featurelayer的这两种查询方式,先贴图给大家看看:

\

实现界面

\

属性查询

\

空间查询

看完了效果,下面说说我的实现思路。

首先,实现查询的关键是Query,属性查询时query.where来实现,空间查询时query.geometry来实现,具体代码如下:

1、属性查询

            on(dom.byId("query"), "click", function(event){
                map.graphics.clear();
                var name = dom.byId("name").value;
                var query = new Query();
                query.where = "name = '"+name+"'";
                city.queryFeatures(query, function(results) {
                    var features = results.features;
                    console.log(features);
                    map.centerAndZoom(features[0].geometry,8);
                    var sms = new SimpleMarkerSymbol(SimpleMarkerSymbol.STYLE_DIAMOND,
                            10,
                            new SimpleLineSymbol(SimpleLineSymbol.STYLE_SOLID,
                                    new Color([0,0,0]),
                                    1
                            ),
                            new Color([255,0,0])
                    );
                    map.graphics.add(new Graphic(features[0].geometry,sms));
                });
            });
2、空间查询

            var draw = new esri.toolbars.Draw(map);
            draw.on("draw-end",addGraphicToMap);
            on(dom.byId("extent"), "click", function(event){
                map.graphics.clear();
                map.setMapCursor("pointer");
                draw.activate(esri.toolbars.Draw.EXTENT);
            });
            function addGraphicToMap(evt){
                map.setMapCursor("default");
                draw.deactivate();
                var sfs = new SimpleFillSymbol(SimpleFillSymbol.STYLE_SOLID,
                    new SimpleLineSymbol(SimpleLineSymbol.STYLE_DASHDOT,
                         new Color([255,0,0]),
                         2
                    ),
                    new Color([255,255,0,0.25])
                );
                map.graphics.add(new Graphic(evt.geometry, sfs));
                //根据空间进行查询
                var query = new Query();
                query.geometry = evt.geometry;
                city.selectFeatures(query, FeatureLayer.SELECTION_NEW, function(results){
                    console.log(results);
                    for(var i= 0,length=results.length;i
完整代码如下:




    
    
    Simple Map
    
    
    
    <script src="http://localhost/arcgis_js_api/library/3.9/3.9/init.js"></script>
    <script src="jquery-1.8.3.js"></script>
    <script src="jquery.page.js"></script>
    <script>
        var map, mapCenter;
        require([
            "esri/map",
            "esri/layers/ArcGISTiledMapServiceLayer",
            "esri/layers/FeatureLayer",
            "esri/layers/GraphicsLayer",
            "esri/graphic",
            "esri/geometry/Point",
            "esri/symbols/SimpleFillSymbol",
            "esri/symbols/SimpleLineSymbol",
            "esri/symbols/SimpleMarkerSymbol",
            "dojo/_base/Color",
            "esri/tasks/query",
            "esri/tasks/QueryTask",
            "dojo/on",
            "dojo/dom",
            "dojo/domReady!"],
        function(Map,
             Tiled,
             FeatureLayer,
             GraphicsLayer,
             Graphic,
             Point,
             SimpleFillSymbol,
             SimpleLineSymbol,
             SimpleMarkerSymbol,
             Color,
             Query,
             QueryTask,
             on,
             dom)
        {
            map = new Map("map", {logo:false,slider: true});
            var tiled = new Tiled("http://localhost:6080/arcgis/rest/services/chinamap/MapServer");
            map.addLayer(tiled,0);
            var labelLayer = new GraphicsLayer();
            map.addLayer(labelLayer,2);
            mapCenter = new Point(103.847, 36.0473, map.spatialReference);
            map.centerAndZoom(mapCenter,4);
            var city = new FeatureLayer("http://localhost:6080/arcgis/rest/services/city/MapServer/0");
            map.addLayer(city);

            on(dom.byId("query"), "click", function(event){
                map.graphics.clear();
                var name = dom.byId("name").value;
                var query = new Query();
                query.where = "name = '"+name+"'";
                city.queryFeatures(query, function(results) {
                    var features = results.features;
                    console.log(features);
                    map.centerAndZoom(features[0].geometry,8);
                    var sms = new SimpleMarkerSymbol(SimpleMarkerSymbol.STYLE_DIAMOND,
                            10,
                            new SimpleLineSymbol(SimpleLineSymbol.STYLE_SOLID,
                                    new Color([0,0,0]),
                                    1
                            ),
                            new Color([255,0,0])
                    );
                    map.graphics.add(new Graphic(features[0].geometry,sms));
                });
            });

            var draw = new esri.toolbars.Draw(map);
            draw.on("draw-end",addGraphicToMap);
            on(dom.byId("extent"), "click", function(event){
                map.graphics.clear();
                map.setMapCursor("pointer");
                draw.activate(esri.toolbars.Draw.EXTENT);
            });
            function addGraphicToMap(evt){
                map.setMapCursor("default");
                draw.deactivate();
                var sfs = new SimpleFillSymbol(SimpleFillSymbol.STYLE_SOLID,
                    new SimpleLineSymbol(SimpleLineSymbol.STYLE_DASHDOT,
                         new Color([255,0,0]),
                         2
                    ),
                    new Color([255,255,0,0.25])
                );
                map.graphics.add(new Graphic(evt.geometry, sfs));
                //根据空间进行查询
                var query = new Query();
                query.geometry = evt.geometry;
                city.selectFeatures(query, FeatureLayer.SELECTION_NEW, function(results){
                    console.log(results);
                    for(var i= 0,length=results.length;i



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